The invention relates to an assembly and device for providing attachment between two objects, such as machine parts. According to the present invention the components can be connected and disconnected simply, yet the connection therebetween is reliable. A wide variety of objects can be attached together practicing the present invention, the attachment having many of the advantages associated with threaded connections (such as fine adjustability and secure attachment), but few of the disadvantages, (no long threaded bores being necessary, and reciprocal movement without rotation being possible over the majority of the length of the fastening movement).
According to the present invention an assembly is provided that includes a first structure, a second structure, and means for attaching the structures together. The first structure includes first and second substantially parallel spaced-apart plates with means defining an aperture in each of the first and second plates. The aperture-defining means includes edge means for each of the first and second apertures for engaging grooves of a conically threaded member and allowing longitudinal displacement of the threaded member upon rotation when in engagement with the edge means. A line perpendicular to the plates passes through the first and second apertures.
The second structure operatively abuts the first structure and has a planar surface portion, a line in the plane of the surface portion passing through both the first and second apertures of the first structure.
The attachment means prevents substantial relative movement between the first and second structures by applying forces to the edge means and surface portion tending to push the surface portion and the edge means apart. Such attachment means includes a conically-shaped, conically-threaded member having a given cone angle, and adapted to engage the edge means and to operatively abut the surface portion. The threaded member is longer than the distance between the parallel plates.
The first aperture is shaped to receive the threaded member and has an area larger than at least the smallest cross-sectional area of the threaded member, and the second aperture is also shaped to receive the threaded member and has an area larger than the cross-sectional area of the threaded member portion adjacent thereto when a portion of the threaded member is received by the first aperture. Thus, the threaded member can be at least partially introduced through the apertures by a mere longitudinal movement, without rotation. The angle formed between a line tangent to the edge means and a line in the plane of the surface portion is equal to the cone angle of the threaded member (preferably about 5 to 10 degrees).
An attachment device according to the present invention consists of the first structure spaced-apart parallel plates, with the cross member rigidly interconnecting the plates, and the threaded member. The angle formed between a line tangent to the edge means and a line passing through one of the edge means and perpendicular to the plates is between zero degrees and the cone angle, depending upon the configuration of the structure to which attachment is to be made.
Preferably, the threaded member is threaded over substantially its entire length, the thread having a uniform pitch, and having flattened thread ridges for engagement of the surface portion of the second structure. The exact positioning of the first and second apertures in the first and second plates will depend upon the configuration of the second structure to be attached thereto.
It is the primary object of the present invention to provide an attachment assembly for simply and easily effecting attachment between first and second structures. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.